Check the Properties of the task in question. If the difference between the CPU time and the Elapsed time is more than a few minutes, that WU has stopped processing. It will proceed no further and should be aborted.

I would also vote for both with two apps, BUT... you really DO need to get your act together on how BOINC works. There is no reason for the "will think it restarts" thing, any more than there is any excuse for the current WUs 'hanging' and having to be aborted. Both are bugs in your code. I realize that the bugs only exist because of VirtualBox, but you chose to use it. Sorry if that sounds harsh, but MANY other projects have dealt with these VB issues, they are well known, they are hard to solve, and even once solved may reoccur with a new version. My normal stance is to refuse to run any VB-based project - but your goals seemed to be worth the "pain" so I joined.